Apparatus for altering the shape and size of alpha projected beam of light



April 1929- H. A. MCGUNNIGLE 1,709,626

APPARATUS FOR ALTERING THE SHAPE AND SIZE OF A PROJECTED BEAM OF LIGHTFiled April 121. 1926 Jwumkom. MZdflMWyzQla Patented A r. 16,1929.

;* UNITED STATES HAROLD A. McGUNNIGLE, on NEW YOBK,N. Y., ASSIGNOR T0AR'ILITE, me, or NEW 7 PATENTOFFICE'.

' YORK, N.'Y., A CORPORATION OF NEW YORK.

APPARATUS FOR ALTERING THE SHAPE AND 5121201 A rnoanornn BEAM or LIGHT.

Application filedApri1.21, 1926. Serial No. 103,547. I

This invention relates to an apparatus for use with light projectionmachines and is particularly adapted to be used in an optical projectionmachine of the type designed for illuminating a field of vision or anobject from a distance with a ro'ected beam of A further object is tocontrol the shape of beam of light projected on a field of vision at anangle to its plane in such manner as to illuminate an area of anydesired shape or size on said field;

Another object is to control a beam of light projected on a field ofvision at an angle to the plane of the field in such manner as toproject a beam having a rhomboidal section.

Another object is to provide a means having a central openingthrouglrwhieh a beam of'light may be projected and including one or moreadjustable light shields movable into and out of the beam adj acent saidopenand another object of the invention is to provide a means having acentral rectangular opening through whicha pyramidal beam of light maylie-projected and including adjustable light shields movable tointersect said opening and angularly adjustable with respect to the sidewalls of said opening.

Other objects of the present invention will appear in'the followingdescription thereof,

reference being had to the accompanying drawing forming part of thisspecification, wherein like reference characters indicate correspondingparts in the several views and I in which form of the supporting disk"for the light shields; and

Figure 5 1s a section taken on the line 55 of Figure 1.

Referring more particularly to the draW- mg, the apparatus comprisesa'suppor-t suchas the plate or disk 5'havinga central opening 6 thereinof any desired shape, preferably square, as shown in Figure 1, or round,as

shown in Figure 1. The disk is mounted in the light projection machinein position to permitthebeam of light to pass through the said openingat right-angles to the plane of the disk. p This disk may be mounted inthe machine in any desired manner depending upon the particular type ofprojection machine used. and described in my copending application,Serial No. 103,546, filedApril21, 1926, which consists in locating thedisk between the con-' densing and projecting lens and attaching it to aring rota'tably mounted on an annular support carried by the lamphousing of the' pro ector unit. For a detailed disclosure of this methodof mountingv the present invention in an optical pro ection machine,reference may be had to the above-noted applicatiojn. I

The disk 5 is also provided with guide slots 7 extending outwardly fromthe center of each side wall facing the opening 6 and'at right anglesthereto. The-disk supports two pairs of light shields 8, each shieldconsist- One preferredmethod is showning of a plate, preferablyrectangular and opaque, mounted for combined rotary and lateral movementin sliding contact with the disk by virtueof the headed pin or rivet 9'secured to the center of the shield and ar ranged to project beyondoneface of the same that side of the opening which it faces. As

stated above, the light shields-are arranged 7 in pairs, one pair beinglocated on one face of the disk5 adjacent opposed sides of the opening 6and the other pair being positioned on the other face of the diskadjacent the other opposed sides of the opening. This ar- .rangementisclearly indicated in F igurel and is such as to permit themanipulation of any-or all of the shields without obstruction from theothers.

The adjusting means for moving each shield 8 to any desired positionover the opening 6 (within the limits of movement'oii the rivet- 9 inits slot 7 is more clearly shown in Figure 2, and, in its preferredform, com prises a fixed swivelled post 11 mounted in an uprightposition on an upset portion 12 of.

the disk 5 near the periphery thereof. The

axial opening 18 in the post and projecting into the annular groove 19formed in the screw adjacent its head 20. The adjusting screw 16 extendssubstantially iarallel to the disk 5 and shield 8 and threaded inthetapped hole 21 ot the swivellcd traveller post 22 mounted on the upsetportion oi? the shieldB. The mounting of the post 22 is similar to thatof the tired post 11, as by the stem 24 extending through the hole 25 inthe shield with its end swaged ()L'lltitdtbtl over in the recess on theopposite side of the shield, as shown. 3

The, movement of each light shield is controlled by two adjusting screws16 each mounted in a fixed post 11 and a traveller post 22 on oppositesides of the guide rivet 9, the post 22 being located near a rear cornerof. the shield.

lVith the construction described the swivelled posts will adjustthen'iselves to prevent binding oi the screws when any one of the pairsof adjustingscrews 16 is turned so to cause rotation of its shield. Eachshield 8 may be moved bodily over the opening 6 by turning both of itsscrews the same amount in the same direction, and this movement can bemade as small as desired. To rotate the shield about its pivot 9, one ofthe screws may be turned in the proper direction or both screws turnedin opposite directions Thus the light shields may be adjusted to variousangular positions, over the opening 6 in the manner indicated in Figure1.

In Figure 3, a side elevation of the apparatus is shown to more clearlvillustrate the relative locations of two adjacent light shields onopposite sides of the disk 5, certain of the adjusting screws 16 andswivellcd posts 11 and 22 being shown in operative position on eachshield.

In Figure & is shown an elevation of a modified form of support or disk5 having a round central opening 6, spaced guide slots 7 and themounting holes ll in the upset portions 12; it being understood, ofcourse, that this form of disk may be substituted as a support for thelight shields and'adjusting means shown in the other figures.

In operatiomthe support or disk-5 is mount-- cd in operative position ina light projecting 'machine (not shown, but preferably of the type shownand described in my copend ing application above referred to) with thebeam of light project-ed through the opening 6 normal to the plane ofthe disk. The size and-shapeot the beam may be altered. by adjustment ofthe light sh iel'ds 8 into and out o'tjthe peripheral portions thereof,the moveprent ol the individual shields being a,ceurately controlled byturning the adjusting screws 16 in the fixed posts 11 swivelled to the;d isk, and thus causing the traveller posts 22 to be moved axiallyalongthe screws andE the shields to be drawn bodily over orrotated on theface of the disk. When once adjusted in this manner the shieldswillremain: in adjusted position without clamping screws or othersccuringmeans. It will also be noted: that the shields are adjustable from theedge of the disk either with a screwdriver or the fingers, such.adjustment being necessary when the apparatus is mounted in the limitedspace between the condensing lens and the projection lens of an opticalprojection machine.

A light projection machine when equipped with an. adjustable lightshield of the type described useful for many practicalpurposes.

being particularly effective for illuminating a field of vision orobjecthaving a specified outline or area. For example, the light of themachine may be adjusted to. illuminate a trained picture or paintingwithin its frame, the projector being mounted in an inconspicuouslocation on a wall or ceiling above and to one side of the line ofsight. Very pleasing effects are produced in this manner because theframe and surrounding objects are not illuminated while the picture orpainting itself is uniformly lighted and prominently displayed.Similarly, an advertisingsign, ex-

hibit or other objector objcetsmay be uniformly and effectivelyilluminated. Furthermore, snchillluninationisveryeconomical sinceasinglesource of light of small candlepower may be utilized to illuminatecomparatively large areas with sufiicient intensity to give effectiveresults.

In the illumination of many objects it is de sirable to place theprojection machine in an inconspicuous location at a distance from theobject as on a side wall, bookcase or other support with the result thatthe beam of light strikes the object at an angle above the line ofsignt. If the beam is projected through a rectangular or round openingitwill illuminate an area on the field of vision which will be, irregularor distorted. This distortion will vary, of course, with the angle ofprojection and it is the purpose of the present in vention to distort oralter the cross-section of the beam itself near the source of light bymeans of the adjustable shields to such an extent as will correctthedistortion of the illuinvention and within the scope of the appendedclaims. v

, Having described the invention what I claim as new and desireto-secure by Letters Patent, is I 1. In a device of, the classdescribed, a supporting disk having a central square opening, aplurallty of guide means extending out- 1 wardly from the sides of saiddisk adjacent said opening, a plurality of. rectangular light shieldspivotally mounted on said guide means, a pair of posts swivelled onupset portions of each shield on opposite sides of said pivotalmounting, apertured posts "swivelled on upset portions of said diskadjacent its periphery, an adjusting screw rotatably mounted in eachapertured post, means for preventing axial movement of the screw in thelast-named post, and means for threadedly engaging said screw 1n thecorresponding post on each shieldwhereb-y to impart movement to theshield upon rotation of either of its adjusting screws.

2. In a device of the class described, a supporting member having anopening, guide means extending outwardly from the sides of said memberadjacent said opening, rectangular light shields pivotally mounted onsaid guide means, posts swivelled. on ofi'set portions of each shield onopposite sides of said pivotal mounting, other posts swivelled on theoffset portions of said supportlng member adjacent its edges, .and meansextending between the complemental of the said posts for adjusting saidshields relative to the opening in said supporting member. V

I In testimony whereof I affix my signature.

HAROLD A. 'MCGUNNIGLE.

